Our studies and those of others have demonstrated cell mediated immune challenge reactions to diverse antigens at tumor sites result in regressions of various types of malignant lesions. We propose to investigate further: 1. Cellular and lymphocyte-derived non-cellular mediators of cell mediated immunity which induce antitumor activities of significance in the regressions of neoplasms. 2. Combinations of immunotherapy with other antitumor treatment modalities in regard to augmentation of effectiveness. The eventual goal is to determine whether immune reactions affecting normal and malignant epidermis can be developed into a model system which may yield further information on fundamental aspects of immunology, tumor biology and their relation to host defense mechanisms.